This invention relates to a process for the preparation of imidazoleacetic acid derivatives from 4-haloacetoacetic acid derivatives and amidines.
Heretofore, imidazole-4(5)-acetic acids, their esters or amides could be produced only at great expense via several stage processes. Furthermore, pressure had to be employed even in the first stage in an autoclave. Multistage processes have been described by W. Schunack [Archiv Pharmazie 307: 470 (1974)], F. L. Pyman [J. Chem. Soc. 99: 668 (1911)], and in European patent application 5528.
As disclosed in Swiss Pat. No. 524,617, a method which at first sight seems readily applicable, namely to react the readily accessible 4-haloacetoacetic acid esters or amides with amidines, in all instances leads instead to 6-ring formation (6-halomethylpyrimidine) because the halogen in these .alpha.-haloketones is not sufficiently reactive.